Prostatic expression of human 5 alpha-reductase type 2 during finasteride therapy: a randomized, double-blind, placebo-controlled study

This study was aimed at exploring the effect of finasteride, a non-steroida l competitive inhibitor of the enzyme 5 alpha -reductase, on 5 alpha -reduc tase type 2 at the mRNA level in human prostate, using an in situ hybridiza tion technique. After randomization, 10 men with benign prostatic hyperplas ia (BPH) received oral finasteride (5 mg daily) and five men with BPH recei ved placebo daily. Careful. clinical examination was carried out and 2 biop sy samples were taken transrectally before the treatment and after 3, 6, an d 12 months of treatment. In situ hybridization was carried out and express ion of 5 alpha -reductase type 2 mRNA was measured. The results showed that finasteride treatment had no permanent effect on expression of 5 alpha -re ductase type 2 in prostatic epithelium, compared with placebo treatment. Ex pression varied during treatment, but there was no clear tendency in this e xpression The signal was localized in the epithelial cells. We conclude tha t finasteride treatment had no clear effect on human 5 alpha -reductase typ e 2 expression in the prostate.